U.S. patent number 6,585,756 [Application Number 09/311,965] was granted by the patent office on 2003-07-01 for implantable lumen prosthesis.
Invention is credited to Ernst P. Strecker.
United States Patent |
6,585,756 |
Strecker |
July 1, 2003 |
Implantable lumen prosthesis
Abstract
The present invention relates to an implantable prosthesis
having a membrane and a fluid channel that are inserted into a body
lumen to maintain fluid flow and support the lumen wall. A
preferred embodiment of the invention includes a mesh membrane or
filter attached to a covered stent. The membrane can be mounted on
a frame formed with a shape memory material that can be delivered
through a catheter into a body lumen. The membrane and the frame
can expand from a delivery state into an expanded state.
Inventors: |
Strecker; Ernst P. (Karlsruhe,
DE) |
Family
ID: |
23209260 |
Appl.
No.: |
09/311,965 |
Filed: |
May 14, 1999 |
Current U.S.
Class: |
623/1.16;
623/1.35; 623/1.36 |
Current CPC
Class: |
A61F
2/0105 (20200501); A61F 2/07 (20130101); A61F
2/01 (20130101); A61F 2/95 (20130101); A61F
2/89 (20130101); A61F 2002/065 (20130101); A61F
2002/075 (20130101); A61F 2/848 (20130101) |
Current International
Class: |
A61F
2/06 (20060101); A61F 2/01 (20060101); A61F
002/06 () |
Field of
Search: |
;623/1.13,1.15,1.16,1.27,1.35,1.36 ;606/200 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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195 31 659 A 1 |
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Mar 1997 |
|
DE |
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0 647 148 |
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Jan 1994 |
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EP |
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0 653 924 |
|
Feb 1994 |
|
EP |
|
0 880 948 |
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Dec 1998 |
|
EP |
|
1 000 590 |
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May 2000 |
|
EP |
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WO 97/09945 |
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Mar 1997 |
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WO |
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WO 98/06355 |
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Feb 1998 |
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WO |
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98/07389 |
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Feb 1998 |
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WO |
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WO 98/33454 |
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Aug 1998 |
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WO |
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WO 98/47447 |
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Oct 1998 |
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WO |
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WO 99/00055 |
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Jan 1999 |
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WO |
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WO 99/39662 |
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Aug 1999 |
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WO |
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WO 99/47071 |
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Sep 1999 |
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WO |
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Other References
Brochure, "A decision for precision," ZA-STENT, Cook, Listen
Understand Innovate..
|
Primary Examiner: Snow; Bruce
Attorney, Agent or Firm: Crompton, Seager & Tufte
LLC
Claims
What is claimed is:
1. A prosthetic device comprising: a frame comprising a plurality
of struts extending radially outward and a membrane extending over
the plurality of struts, the frame having a perimeter; at least one
stent having a lumen therethrough, the at least one stent having a
proximal end and a distal end, the proximal end of the at least one
stent connected to an opening in the membrane; a securing element
located proximally of the frame, the securing element having at
least one point of attachment to the frame at a location spaced
away from the perimeter of the frame.
2. The prosthetic device of claim 1 wherein the frame and the
membrane have a delivery position and an expanded position.
3. The prosthetic device of claim 2 wherein the delivery position
has a diameter of 12 French or less.
4. The prosthetic device of claim 1 wherein the frame further
comprises a shape memory material.
5. The prosthetic device of claim 1 wherein the plurality of struts
further comprise a plurality of loop shapes.
6. The prosthetic device of claim 1 wherein the membrane further
comprises a mesh.
7. The prosthetic device of claim 1 wherein the membrane further
comprises a non-permeable material.
8. The prosthetic device of claim 1 wherein the membrane extends
beyond the perimeter formed by the plurality of struts.
9. The prosthetic device of claim 1 wherein the at least one stent
further comprises a flexible shape memory material.
10. The prosthetic device of claim 1 wherein the stent further
comprises a mesh material.
11. The prosthetic device of claim 1 wherein the proximal end of
the stent further comprises a taper.
12. The prosthetic device of claim 11 wherein the taper of the
stent decreases to a diameter at the proximal end by a range of
5%-15%.
13. The prosthetic device of claim 1 wherein the securing element
further comprises a plurality of anchors.
14. The prosthetic device of claim 1 wherein the securing element
further comprises a shape memory material.
Description
BACKGROUND OF THE INVENTION
Various prosthetic devices have been developed for the treatment of
vascular disease. These include self expanding stents that can be
compressed and introduced into the vascular system using catheters.
When the catheter is positioned percutaneously or by other
techniques at the required site, the stent is released and the
catheter is withdrawn.
The stents or prostheses have been developed to treat particular
forms of vascular disease including weakened or occluded blood
vessels or arteries. The treatment of a stenosis or aneurysm, for
example, using a tubular prosthesis can reduce the risk of an
embolism or rupture of the aneurysm. In an abdominal aortic
aneurysm, for example, a bifurcated tubular sleeve can be used to
maintain blood flow between the aortic artery and the iliac
arteries.
However, a continuing need exists for further improvements in
devices and methods of using implantable prostheses for the
treatment of various conditions.
SUMMARY OF THE INVENTION
This invention relates to an implantable prosthesis including a
membrane or filter and a fluid flow channel to control the flow of
fluid through a body lumen. A preferred embodiment of the invention
uses a mesh membrane connected to a stent and, more particularly,
to a stent used to bypass an aneurysm. In a preferred embodiment of
the invention, the fluid flow channel, or stent, is coupled to the
filter. The device includes, in a preferred embodiment, a frame
having a plurality of struts, the struts conforming to the shape of
the inner wall of a vessel, a membrane covering the struts, at
least one tubular prosthesis or stent being aligned with and
connected to an aperture in the membrane and an attaching mechanism
that connects the membrane to the tubular section.
In one embodiment, the device is collapsible to fit inside a
catheter. In a preferred embodiment, the device is collapsible to a
diameter of 12 French or less. The frame and/or the tubular
prosthesis can be a device such as that described in International
Application No. PCT/DE/00226 filed on Jan. 24, 1998, and also
described in U.S. application Ser. No. 09/250,714, filed on Feb.
16, 1999 the entire contents of these applications being
incorporated herein by reference. The stent and the frame of the
filter or membrane can comprise a shape memory material such as a
nickel-titanium alloy.
In a preferred embodiment, the frame comprises a double coil as
described and illustrated in the above incorporated applications.
One of the coils can be covered with a membrane material. In one
embodiment, there can be an oblique angle between the two coils up
to and including, for example, a 90-degree angle.
The struts of the frame can radiate outwardly from a center point
of the frame. In this embodiment, the perimeter formed by the
struts conforms to the shape of the inner wall of a vessel. In a
preferred embodiment, the shape of the perimeter formed by the
struts is circular. In another preferred embodiment, the struts
comprise a plurality of loop shapes.
The membrane material can comprise either a mesh material or a
non-permeable material. In a preferred embodiment, the membrane
material extends beyond the perimeter formed by the struts of the
frame. The additional membrane material allows the vessel to become
completely sealed to prevent leakage between the membrane and the
vessel wall.
The stent can comprise a flexible material. In a preferred
embodiment, the device comprises two stents to be used to bypass an
aneurysm located at a bifurcation. The stent can also comprise an
attachment mechanism to secure an end of the stent to the
membrane.
The stent can be attached to the membrane and/or a vessel wall
using an adhesive such as a polymer. The polymer can also be used
to secure the stent to a double coil membrane. After insertion of
the prosthesis, the adhesive can be injected in fluid form into the
cavity with a catheter and then hardened in situ.
The invention also relates to a method for treating a body lumen
using an implantable prosthesis. The invention can relate to a
method for deploying a prosthesis within a body lumen. This method
can include the use of one or more catheters to deploy the elements
of the prosthesis. The invention can also relate to a method for
attaching at least one stent to a membrane. This method can involve
deploying a membrane in a vessel, forming an opening or aperture in
the membrane, and connecting a stent to the membrane wherein the
tubular path through the stent is coaxially aligned with the
aperture.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a cross sectional lateral view of an aneurysm
stent secured within an aorta;
FIG. 2 illustrates an embodiment of the stent portions attachment
to a membrane
FIG. 3 shows a top view of an aneurysm stent secured within an
aorta.
FIG. 4 shows an oblique view of a double coil stent in an expanded
state.
FIG. 5 illustrates a double coil stent in a non-expanded state.
FIG. 6 shows a front view of an alternate embodiment of a double
coil stent in an expanded state.
FIG. 7 shows a side view of an alternate embodiment of a double
coil stent in an expanded state.
FIG. 8 illustrates an embodiment of a membrane attachment mechanism
for a stent.
FIG. 9 illustrates an alternate embodiment of a membrane attachment
mechanism for a stent.
FIG. 10 illustrates an alternate embodiment of a membrane
attachment mechanism for a stent.
FIG. 11 shows an embodiment of a membrane that can have one or more
slits.
FIG. 12 shows a double coil stent with a bifurcation stent engaged
at an aneurysm site.
FIG. 13 shows a top view of the prosthesis illustrated in FIG.
12.
FIG. 14 illustrates an embodiment of a temporary membrane
filter.
FIG. 15A illustrates coaxial stents attached to multiple
filters.
FIG. 15B shows an alternate embodiment for a mesh with attached
stent.
FIG. 16 shows a schematic representation of a method for treating a
body lumen.
FIG. 17 illustrates a schematic representation for deploying a
temporary prosthesis within a body lumen.
FIG. 18 illustrates a method for attaching at least one stent to a
membrane.
The foregoing and other objects, features and advantages of the
invention will be apparent from the following more particular
description of preferred embodiments of the invention, as
illustrated in the accompanying drawings in which like reference
characters refer to the same parts throughout the different views.
The drawings are not necessarily to scale, emphasis instead being
placed upon illustrating the principles of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates an embodiment of an aneurysm stent 10. In this
embodiment, the aneurysm stent 10 comprises a frame 12 having a
plurality of struts 14 and being covered by a membrane 16. The
frame 12 can comprise any biocompatible material. A bifurcation
stent 18 comprising a first stent portion 20 and a second stent
portion 22 form an aperture in the membrane 16 and are secured
therein. Also in this embodiment, the aneurysm stent 10 comprises a
securing mechanism 24 which secures the stent 10 to an aorta wall
26.
In one embodiment, the aneurysm stent 10 is collapsible to fit
inside a catheter. In a preferred embodiment, the stent 10 is
collapsible to a diameter of 12 French. The frame 12, membrane 16
and securing mechanism 24 can comprise a shape memory material. In
this embodiment, the frame 12, when removed from a catheter,
expands into a predetermined shape.
The struts 14 of the frame 12 can radiate outwardly from a center
point of the frame 12. In this embodiment, the perimeter formed by
the struts 14 form a shape which conforms to the shape of the inner
wall of an aorta wall 26. In a preferred embodiment, the shape of
the perimeter formed by the struts 14 is circular. In another
preferred embodiment, the struts 14 comprise a plurality of loop
shapes.
The membrane 16 can comprise either a mesh material or a
non-permeable material. The mesh material can allow for obstruction
of clots while allowing the flow of fluids through the vessel. The
non-permeable material occludes the flow of any substance through
the vessel.
The mesh material can have mesh holes the size of 0.2 to 1.0 mm. In
one embodiment, the mesh is knitted or weaved. In this embodiment,
when the stent 10 is inserted into a lumen, the lumen walls will
cause the stent 10 to compress, thereby causing the mesh holes to
become smaller.
To create a sealing between the frame 12 and the first 20 and
second stent portions 22, the mesh material can be thrombogenic.
The sealing can be created by a rough texture of the surface of the
mesh material. In one embodiment, the rough texture is created by a
textile material like wool. The rough texture can also be created
by a material where the mesh filaments consist of multiple threads.
The sealing can also be created by covering the mesh filaments with
a thrombogenic substance or a sealing drug. In an alternate
embodiment, the sealing can be created when the mesh filaments are
made of an elastic material, such as silicone, or when the mesh
filaments are formed of textile filaments and elastic
filaments.
In a preferred embodiment, the membrane 16 material extends beyond
the perimeter formed by the struts 14 of the frame 12. The
additional membrane material 16 allows the vessel to become
completely sealed.
The first stent portion 20 and the second stent portion 22 of the
bifurcation stent 18 can comprise a flexible material. In a
preferred embodiment, the device comprises two stents to be used to
bypass an aneurysm 28 located at a bifurcation 30. In this
preferred embodiment, first stent portion 20 and the second stent
portion 22 of the bifurcation stent 18 carries blood from the aorta
32, past the aneurysm 29 and to the bifurcation 30. This process
reduces the pressure at the aneurysm site 29 and will help prolong
the life of the aneurysm 29. The process will also help to decrease
the risk of aneurysm 29 rupture. The first 20 and second 22 stent
portions of the bifurcation stent 18 can be made from a mesh
material. This material can be, but is not limited to, a fabric
material or a plastic material.
The securing mechanism 24, in one embodiment, comprises a series of
arms or connectors 34 which attach the aneurysm stent 10 to the
aorta wall 26. This can be accomplished using small hooks or
barbs.
FIG. 2 illustrates a preferred embodiment of the first 20 and
second 22 stent portions attachment to the membrane 16. In this
embodiment, the proximal ends of the stents 20, 22 are funnel
shaped which prevents the stents 20, 22 from translating past the
membrane 16. In an alternate embodiment, the ends of the stents 20,
22 comprise a plurality of anchors which also prevent migration of
the stents 20, 22. In an alternate embodiment, the proximal ends of
the stents 20, 22 are tapered. In a preferred embodiment, the ends
can be reduced in area by 5%-15%, for example.
FIG. 3 illustrates a top view of the aneurysm stent 10. In this
embodiment, the loop pattern of the struts 14 of the frame 12 is
shown. Membrane material 16, in this embodiment, hangs past the
perimeter created by the struts 14 to create a secure seal of the
aneurysm stent 10 when placed in an aorta.
FIG. 4 illustrates an oblique view of a double coil stent 100 in an
expanded state. In an embodiment of the invention, the double coil
stent 100 has a first end 102 and a second end 104. The stent 100
also include a first coil 106 and a second coil 108. In a preferred
embodiment, the first 106 and second 108 coils can have an oblique
or circular shaped. The first 106 coil and second 108 coils can be
used to support the inner wall of a vessel, such as an artery.
The coils 106 and 108 of the double coil 100 are attached at a
connection site 110. There can be a 90-degree angulation between
the connection site 100 and the first 106 and second 108 coils in
the stent's 100 expanded state. In a preferred embodiment, the
connection site 110 consists of two wires, one wire derived from
the first coil 106 and the second wire derived from the second coil
108. The two wires can be connected together by a third wire
wrapped around the connection site 110. In a preferred embodiment,
the third wire is a thin nitinol wire. One of the coils 106, 108
can be covered by a membrane material 112. In a preferred
embodiment, the membrane material 112 comprises a mesh. The mesh
material can be semipermeable, to allow blood flow and prevent the
travel of clots. The mesh also can be impermeable to all
materials.
In an alternate embodiment, one of the coils 106 can be covered
with the semipermeable material and the other coil 108 can be
covered by an impermeable material. In another preferred embodiment
of the invention, the membrane material 112 is secured to the coil
108. The membrane 112 material can be secured to the coil 108 by an
adhesive in one embodiment. The membrane 112 can also be melted
onto or fused to the coil 108 in alternate embodiments. The
membrane 112 can also contain a seam which wraps over the coil 108
and secures it to the coil 108. The membrane can also be sutured
onto the stent strut. The stent strut can also be incorporated into
the membrane. The mesh can be knitted or weaved around the stent
strut.
In a preferred embodiment, the double coil stent 100 can have barbs
or anchors 103 to prevent dislocation of the stent 100 after
implantation. The barbs 103 can be welded to connection sites on
the double coil stent 100. The barbs 103 can be made from an
elastic material, to allow ease of placement inside a catheter. In
a preferred embodiment, the barbs 103 are made from thin nitinol
wires. In another preferred embodiment, the double coil stent 100
has a hook 105 to improve stability and prevent dislocation of the
stent 100. The hook 105 can be attached to the second end 104 of
the stent 100 and extend towards the first end 102.
The double coil stent 100 itself, in a preferred embodiment, is
made of a wire material such as a nickel-alloy. The wire preferably
comprises a shape memory material such that when the stent 100 is
collapsed, it will return to a predetermined shape.
FIG. 5 shows a double coil stent 100 in a non-expanded state within
a catheter 114. The stent 100 can comprise a first coil 106 and a
second coil 108 joined at a connection site 110. One of the coils
can be covered by a membrane material 112, preferable a mesh
material. In this embodiment, the first coil 106, the second coil
108, and the membrane material can be collapsed to fit the stent
100 within a catheter 114. The stent 100 can be compressed to fit
into a catheter 114 having a diameter of 8 french (2.4 mm) for
insertion into an aorta. However, the stent 100 can be compressed
to fit into catheters from 0.5 mm to 5.0 mm in diameter generally,
depending on the cross section of the artery to be treated and the
diameter of the struts needed to create a firm suspension of the
device. The connection site 110 between the first 106 and second
108 coils, in this embodiment, allows the coils 106, 108 to expand
beyond their uncompressed 90-degree angulation. When the stent 100
is introduced into the catheter 114, the hook 105 can be positioned
parallel to the second end 104 of the stent 100 and will not
significantly increase the diameter of the collapsed stent 100.
FIGS. 6 and 7 illustrate an alternate embodiment of a double coil
stent 120. The double coil stent 120 comprises a shape memory
material. In a preferred embodiment, this material can consist of
metal wire. Other materials can be used, however, such as plastic.
The stent 120 has a first end 122 and a second end 124. The stent
material can form a first loop 126 and a second loop 128. The loops
126, 128 compensate for alterations of the material lumen or
irregular vessel lumina. The loops 126, 128, in a preferred
embodiment, are connected at a first connection site 130 and a
second connection site 132, respectively. The stent 120 can also
comprise a membrane material 134. In a preferred embodiment, the
membrane material 134 is a mesh material. In this embodiment, the
mesh can be semi-permeable to allow fluids, but not clots, to pass
through a vessel. The mesh can also be impermeable to provide
occlusion of a vessel. The mesh can also become impermeable over
time, after being implanted as permeable, by the formation of blood
clots at the mesh filaments to provide occlusion of a vessel.
FIGS. 8, 9 and 10 illustrate embodiments for a double coil stent
with a bifurcation stent. FIG. 8 shows a double coil stent with a
bifurcation stent 150 mounted within an aortic lumen 152. The stent
150 comprises a double coil stent 154 fitted to an aortic wall 156.
In a preferred embodiment, the deployed double coil stent 154
comprises waves or undulations 157. The stent 150 can also comprise
a bifurcation stent 158 having a first stent portion 160 and a
second stent portion 162. In this embodiment, the membrane 164 of
the double coil stent 154 comprises a dome shape which is
accommodated to the flow dynamics of blood. The first 160 and
second 162 stent portions of the bifurcation stent 150 are attached
to the membrane 164 by funnel portions 166 on the ends of the stent
portions 160, 162 to prevent any backsliding of the stent. The
first 160 and second 162 stent portions can also comprise anchors
168, preferably barbs, below the membrane 164 to prevent sliding of
the stent portions 160, 162 through the membrane 164. In its
unexpanded state, the anchors 168 will lie parallel to the body of
the bifurcation stent 158. When the double coil stent with the
bifurcation stent 150 is removed from a catheter housing, the
anchors 168 will move outwards because of their elastic tension and
prevent sliding of the first or second stent portions 160, 162.
FIG. 9 shows an alternate embodiment of a double coil stent with a
bifurcation stent. In this embodiment, the first 160 and second 162
stent portions of the bifurcation stent 158 comprise anchors 168 to
prevent the stent 158 from sliding and becoming disengaged from the
membrane 164.
FIG. 10 shows another alternate embodiment of a double coil stent
with a bifurcation stent. In this embodiment, the membrane 164
comprises a double valley membrane. In this embodiment, the first
160 and second 162 stent portions of the bifurcation stent 158 can
be secured to the membrane 164 by either a funnel portion or by
anchors 168.
FIG. 11 shows an embodiment of a membrane 180 to be used with a
stent such as a double coil stent or with a bifurcation stent. In a
preferred embodiment, the membrane 180 comprises a first slit 182
which dilates to receive an expanded stent. In an alternate
embodiment, the membrane 180 can comprise two parallel slits to
receive two stents. In an alternate embodiment, a second membrane
fits above the first membrane 180 and comprises a second slit. The
two membranes form a tight seal between the occluder lumen walls.
In a preferred embodiment, the membranes are silicone.
FIG. 12 shows a double coil stent with a bifurcation stent engaged
at an aneurysm site 190. The double coil stent 192 in this
embodiment comprises a first coil 194, a second coil 196, and a
membrane 198. The double coil stent 192 secures the bifurcation
stent 200 within the aorta. The bifurcation stent 200 comprises a
first stent portion 202 and a second stent portion 204 which are
mounted within the membrane 198. The first 202 and second stent 204
portions of the bifurcation stent carry blood from the aorta 206,
past the aneurysm site 190 and to the first 208 and second 210
bifurcation portions. This process reduces the pressure at the
aneurysm site 190, helps prolong the life of the aneurysm and
reduces the risk of rupture of the aneurysm.
In a preferred embodiment, the first stent portion 202 and the
second stent portion 204 are arced to provide for ease of insertion
into the first 208 and second 210 bifurcation portions,
respectfully. When inserted into the bifurcation portions 208, 210,
the stent portions 202, 204 form a fluid seal 205. The seal
substantially reduces or eliminates endoleakage or discharge of the
fluid flowing through the stent portions 202, 204. In another
preferred embodiment, the first 202 and second 204 stent portions
are comprised of a mesh material 209. This material can comprise a
fabric material. The material can also comprise a plastic material.
In another preferred embodiment, the mesh material 209 is covered
by a second material 207. The second material 207 provides for
strength of the stents 202, 204 while allowing them to retain
flexibility.
FIG. 13 illustrates a top view of the membrane 198 having the first
202 and second 204 bifurcation stent portions secured therein. In
this embodiment, the membrane occludes blood flow through the
aneurysm 190 and forces the blood to flow through the first 200 and
second 204 bifurcation portions.
FIG. 14 illustrates a removable membrane mesh filter 220. The
filter 220 comprises a coil loop 222 attached to a coupler 224
which can be deployed and withdrawn through a catheter 226. The
coupler 224 can be either flexible or rigid. The coupler 224 can
also provide for axially distancing stabilizing member from frame.
The coil loop 222 comprises a membrane 228. In a preferred
embodiment, the coil loop 222 is a nickel-alloy wire loop. In
another preferred embodiment, the membrane 228 is a textile
mesh.
The filter 220 can comprise a basket shape for the membrane 228 to
allow for clot removal. The filter 220 can also be inserted from
below to remove debris. In an alternate embodiment, lysing agents
can be delivered through the catheter in order to perform clot
lysis. The removable membrane mesh filter 220 can be deployed in an
aorta lumen 230 to serve as a filter in the case of an emergency
treatment such as an embolism. An impermeable membrane can be used
to occlude the aorta to provide emergency treatment of a ruptured
aneurysm.
FIG. 15A illustrates an alternate embodiment of the invention
comprising a coaxial stent prosthesis 300. The coaxial stent 300
comprises a plurality of stents 304 coaxially mounted to a
plurality of membranes 306. In a preferred embodiment, two stents
304 are mounted coaxially to three membranes. The membranes can be
affixed to a wire material 308. When deployed, the wire material
308 of the prosthesis 300 becomes secured to the wall 310 of a
lumen 312. In a preferred embodiment, the membranes 306 comprise a
filter mesh. In an alternate embodiment, the membranes 306 comprise
a non-permeable material. The membranes 306 can have different
diameters, corresponding to the diameters of an aneurysm. Thus, the
membrane 306 in the middle of FIG. 15A can have a larger diameter
than the upper and lower membrane. When deployed, this embodiment
can divide an aneurysm into two chambers. Blood can thus reenter
into just one chamber of the aneurysm instead of the entire
aneurysm. Reperfusion of the aneurysm by lumbar arteries or by the
inferior mesenteric arteries can be of less importance. The
chambers created between the membranes 306 can be filled with an
adhesive such as a curable polymer to provide for a firm connection
of the membranes to the aortic wall.
FIG. 15B shows another alternate embodiment of a double coil stent
with a bifurcation stent 300. In this embodiment, the double coil
stent with a bifurcation stent 300 is mounted within an aortic
lumen 312. The stent 300 has a double coil stent 304 fitted to an
aortic wall 310. The double coil stent 304 has a first wire loop
318 and a second wire loop 320 covered by a first membrane 314 and
a second membrane 316, respectively. The double coil stent 304 also
has a wire strut 306 connecting the first 318 and second 320 wire
loops. In this embodiment, a bifurcation stent 302 having a first
bifurcation portion 322 and a second bifurcation portion 324, is
attached to the double coil stent 304, through the first 314 and
second 316 membranes. The bifurcation stent 302 passes through both
membranes 314, 316 to form an improved connection for and prevent
any dislocation of the first 322 or second 324 bifurcation
portions.
The space 326 between the first wire loop 318 and the second wire
loop 320 can be filled with a polymer 308. The polymer can cure in
this space 326 which provides a firm connection among the aortic
wall 310, the bifurcation stent 302 and the membrane or double coil
stent 304. The polymer 308 can be installed by perforation of the
second membrane 316 with a distally introduced catheter. Through
the end hole of the catheter, the polymer 308, in its fluid state,
can thereby be injected into the space 326. The polymer 308 can be,
but is not limited to, either polymer silicone, acrylate glue,
ETHIBLOC.TM., gelatine or gelatine sponge. In a preferred
embodiment, the polymer 308 does not act as a plug, but functions
to connect any implanted parts to a vessel wall. The polymer can
assist in sealing against leakage.
In addition to a polymer curing in the chamber between the
membranes, also, note the use of wire coiling 305 instead of, or in
addition to the polymer. Wire coiling is a procedure to treat
aneurysms. A surgeon can introduce wire coils into the aneurysmal
sack to create thrombosis within the peripheral parts of the
aneurysm and to provide flow within the centre. In case of wire
coils within one of the chambers as shown in FIG. 15B, the blood
flow is provided through the stent in the centre of the chamber
without any disturbances by the coils surrounding the stents. Wire
coils have the advantage of easy handling. The coils can be
inserted through a catheter like the polymer. Migration of the
coils is unlikely, particularly when used with a polymer. The
polymer can embolize before curing. Embolization coils including a
wire with a rough surface e.g. wool filaments creates a thrombosis
within the chamber.
FIG. 16 shows a schematic representation of a method for treating a
body lumen. First, the user provides a catheter and a prosthesis
having a frame, a membrane and at least one stent 238. Next, the
user attaches the at least one stent to the membrane 240. Next, the
user compresses the prosthesis into the catheter 242 and introduces
the catheter into a lumen 244. The user can then remove the
catheter from the prosthesis 246 and allow the prosthesis to expand
and secure itself to the lumen 248. Next, the catheter can be
removed from the lumen 250. Lastly, the prosthesis is allowed to
direct a fluid flowing within a lumen to flow through at least one
stent 252. In a preferred embodiment, the at least one stent
directs the fluid across an aneurysm.
FIG. 17 illustrates a schematic representation for deploying a
temporary prosthesis within a body lumen. First, the user provides
a catheter and a prosthesis having a frame, a membrane and a
connector 260. Next, the user loads the prosthesis into the
catheter 262 and introduces the catheter into a lumen 264. The user
can then remove the catheter from the prosthesis 266 and allow the
frame and membrane to expand 268. Next, a fluid flowing through the
lumen can be filtered by the prosthesis 270. When the filtering
process has been completed, the user can slide the connector into
the catheter and compress the frame and membrane within the
catheter 272. The user can then remove the catheter from the lumen
274. In a preferred embodiment, the membrane comprises a mesh
material.
FIG. 18 illustrates a method for attaching at least one stent to a
membrane. First, the user provides a membrane and at least one
stent 280. Next, an aperture is formed in the membrane 282 and the
stent is provided with an attachment mechanism 284. The stent can
then be placed through the aperture in the membrane 286 and
attached to the membrane 288. In one preferred embodiment, the
attachment mechanism comprises an anchor. In another preferred
embodiment, the attachment mechanism comprises a funnel portion
connected to the stent.
While this invention has been particularly shown and described with
references to preferred embodiments thereof, it will be understood
by those skilled in the art that various changes in form and
details may be made therein without departing from the spirit and
scope of the invention as defined by the appended claims.
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